Atomic Structure

Question 1

Charge and mass of proton, electron, neutron

Answer 1

Proton: +1 and 1
Neutron: 0 and 1
Electron: -1 and 1/1840

Question 2

Describe the basic structure of the atom

Answer 2

Central nucleus contain protons and neutrons with electrons surrounding in shells

Question 3

What is mass number

Answer 3

Number of protons and neutrons

Question 4

What is atomic number

Answer 4

Number of protons

Question 5

What are isotopes

Answer 5

Atoms with same number of protons but different umber of neutrons

Question 6

What is relative atomic mass

Answer 6

Average mass of an element relative to 1/12th of the mass of a carbon-12 isotope

Question 7

What is the mass spectrometer used for

Answer 7

Identifying elements and determining relative molecular mass

Question 8

What are the four parts of the TOF mass spectrometer

Answer 8

Ionisation, acceleration, ion drift and detection

Question 9

What occurs in ionisation (electron impact)

Answer 9

The sample is vaporised and high energy electrons are fired at it, which knocks off one electrons from each particle

Question 10

What occurs in ionisation (electrospray ionisation)

Answer 10

The sample is dissolved in a volatile solvent and forced through a hollow needle, connected to the positive terminal of a voltage supply. Electrons are lost to the positive terminal, producing positively-charged droplets.

Question 11

What occurs in acceleration

Answer 11

The positive ions are attracted to a electric plate with a hole in the middle. All ions have constant kinetic energy

Question 12

What occurs in ion drift/deflection

Answer 12

The ions form a beam through the hole, where lighter ions travel faster due to smaller mass. Then deflected by a magnetic field

Question 13

What occurs in detection

Answer 13

The lighter ions arrive first and they pick up an electron from the detector. This flow of electrons creates a charge and current flows

Question 14

What does the mass spectrometer give accurate information about

Answer 14

Relative isotopic masses and relative abundance of isotopes

Question 15

Describe the axis on a mass spectra of elements

Answer 15

Relative abundance on y and mass/charge ratio on x

Question 16

What is an issue with electrospray ionisation

Answer 16

All masses of isotopes are increased by one as they accepted a hydrogen ion, to become ionised

Question 17

What is an orbital

Answer 17

A volume in space which an electron fills

Question 18

What do the shapes of orbitals represent

Answer 18

The space in which there is a 95% chance of finding an electrons there

Question 19

What is the order of electrons filling in energy levels

Answer 19

1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p

Question 20

Define first ionisation energy

Answer 20

The amount of energy required to remove 1 mole of electrons from 1 mole of gaseous atoms to form 1 mole of ions with 1+ charge

Question 21

Describe the successive ionisation energies of sodium

Answer 21

An increasing trend, with larger increases after each electrons level

Question 22

Describe the ionisation energies in period 3

Answer 22

Increasing trend, but some fluctuation due to electrons entering a new empty orbital

Question 23

Describe the ionisation energies in Group 2

Answer 23

Decreasing trend as the outer electrons get further from the nucleus

Question 24

What does ionisation energy depend upon

Answer 24

Charge of nucleus, distance of electrons from nucleus, shielding

Question 25

What is the electron configuration of chromium

Answer 25

Cr is [Ar] 4s1 3d5

Question 26

What is the electron configuration of copper

Answer 26

Cu is [Ar] 4s1 3d10

Question 27

State symbol for all things in ionisation energy

Answer 27

Gaseous (g)

Question 28

Why does Cl- ion have a larger atomic radius than a Cl atom

Answer 28

Cl- has more electrons, so more repulsion between electrons

Question 29

What does the mass spectrum of Cl2 look like

Answer 29

Peaks at m/z = 70, 72 and 74 in the ratio 9:6:1